Breathing apparatus



March 1, 1932. w. TAMM BREATHING APPARATUS Filed April 11, 1928 /m/enzor.- Wilhelm, m m 0&4?? 55%,

l rn @g5 Patented Mar. 1, 1932 7 STATES PATENT(.OFFICE WILHRDivI` TAMM, orv KIEnsRRMANL AssIGNoRDY DIRECT AND MEsNE AssreN- MENTS, To DEUTSCHE GAsGLHLIcHT-AURR-GESELLSGHAFT MIT BESCHRNKTRR HANTUNGF,,01T RERLINGRRMANA CORPORATION or GERMANY..

BREATHING ARPARATUS Application ldf'April 11, l1,928, Serial No. 269,249andl in Germany September 29,' 1927.',

- Itis known towremove the dangerof Jche vafcmimulation vof nitrogen in breathing; devices/operated automatically `by the lungs of thebearerfbywcausing, while 'eXhaling,. a -porr 5 tionf4 of the: exhaled; air'to pass from4 the circulation system inithe deviceinto the open air byL-means of vazsoe'callefd scavenginggvalve. The known; scavenging valves are based. on thefpri-nciplethat; a: viailvef-will: open: a, finely calibrated: boring as soonasl there is any sup erpressure` in :the v1,cycle of "operation, land that the said boring willfrbev closed` when the `pressuredrops'.belowthe normal, so-'that a "portionzofftheiairrinithe devicewill pass into the yatmosphere through; said! boring: when -tlie=valveis1open. scavenging valves ofthis ktype showcertainA drawbacks, whichare enl tirely removed v by the present-invention A'lo fmake clearer the improvement over prion devices eiiect'ed by the. presentA invention; ,the :drawbacks and sources of .danger of the known Vscavengingl valves .i will VfirstV` be pointedrout. n

It: is required.unconditionally of" a; wellf` 'working-'scavenging valve that: .itl open at each.l exhalation andclose tightly at.` veach drawing in ofvairror oxygen; With thefhithertoknown scavenging valves operating 'la-utomatically, there is available as motive-:powerf only the' difference in, pressure caused betHWeenrthe atmospheric pressure and that eX- istingfwithin thefdeviceby the resistance of thewsaiddevice. -When' the breaths arefsmall such: diierences of pressure'may bel eXtra- Y ordinarilyfsmalll -I' 3 to .lmillimetresfof wa- 'tercelnmn). Itis=obvious that the constructionjofavalve which will have to Vbe sensitive'` to suchl :feeble forces, will give risev to considerable= diliiculties,` and the supervision oii'suchawalve willicall forl specialia'ttention. IIfor?instance1'theY loading 'spring of the scavenging valve isa little too strong, vthe saidvalvewill'not ,open at all at suchfsm'all pressurefdierences. If, on the other hand, said spring'isstooweak, the valvepwillnot closet-'ati pressuresy onlysl-ightly below normal, .-andfin such 'case .the scavengingfwillfbei come delusiver because, .while at each exhalingra-i portiongofthewair v:from the device.;l will vpassintothe atmosphere',` during# drawing 'the borings Aare-very finelycalibratedyand -again impossible.

with a rubber diaphragm the disadvantage exists, that theY rubber will gradually `grow hard, b y which.theelasticityo saidl'diaphragm will decrease and larger pressures will `be required for, operating said valve.v` 'Izt' a diaphragm of micais used there is thedaniger to be'reckoned with, that the inevitable condensation of watery will c'ause-thevalvedisc to Vstickto itsseat on accountnof the'very high adhesion, so that while a high degree of tightness is obtainedat a pressurebelownorf mal, thereisa considerably greater vamount of power required for opening it, whichfliovv-i ever isV not available whenthe vwearer isperformingA light work andv consequently: is

breathing; easily. A further dangerexistsin thefa'ct that in all knownscavenging valves lconsiderable pressure will be required Alto force saidplugs out of the.saidborings.- Y

v All vthese drawbacks are obviated by the present invention, several embodiments of which are illustratedfby waynof'exampleon the accompanying drawings; In saiddraw- Figure l shows-diagrammaticallyithe con'- struction oa-breathing device in accordance with the presentinvention r Figure la shows a :detailof Figl."

Figures 2, 3, and show four'additiona-l modesof execution;V

f In all of the embodiments illustrated` the operation ofthe scavengingfvalve isfefe'cted through an element which directlyyorindirectly closes `the Ibreathing.'cycle either Ytotally or partially. In Figure the valvezdiset of the exhaling valve ais connected with'thefdisc 'nair a Corresponding' quantita7 wilt-.How back again. `In scavenging valves-provided rod c in sucha mannenthat the` scavenging closed, but if the latter is opened the said scavenging valve s will also be opened.

In the modification shown in Figures 1 and la there is provided concentrically with the seat Z ofthe exhaling valve t a second seat e, from which a pipe f leads to the calibrated boring g Whose cross-sectional area is adj usted to control the amount of air discharged by the scavenging valve. As soon as the valve disc t opens during exhaling, the passage into the open air through the'pipe 7 and the calibrated boring g is opened simultaneously, so that the necessary scavengingquantity can flow out. -It willbe understood that theiresistance to the flow of air through the usual carbon dioxide absorbing cartridge is greater' than through the pipe f, so that escape of a portion of the exhaled air through such pipe is insured.l A Y l The modification shown in Figures 2 and 3 are similar in principle to that shown in Figures l and la; only the arrangement of the valve is of different design. In the device according to Figure 2 the exhaled air iows through the pipe L against the rubber diaphragm z',- which is jammed air-tight between the annular-bodies and Z in such a manner, that it will close the concentrical valve seats m and a in its position of rest. In consequence of the exhaling pressure the diaphragm is lifted from the seats. The exhaled air Flows between the said seats through the pipe o. That portion required for scavenging purposes flows simultaneously into the atmosphere through the pipe f. In Figure 3 there is provided in lieu of the movable diaphragm e' a rigid valve disc 79. i As soon as a superpressure-is set up on the left side of the valve disc 70 owing to the exhalation, the said disc will be lifted from the two seats, permitting simultaneously the passage of the major portion of the exhaled air into the circulating system and the remaining portion into the pipe In the modication shown in Figure 5 the operation of the scavenging valve s is eifected by means of a special throttling member in the form of a disc g, which is connected with the scavenging valve s through a rod c guided in the bridge 7'. In the closed position of the scavenging valve s the disc gg will either totally or partially close the cross-sectional area of the breathing duct. During exhalation the superpressure setup below the disc g will cause an axial rising of the disc'g so that a larger cross-section is available for the passage of the exhaled air. At the same time the scavenging valve s is also opened to a corresponding extent. During stronger breathing, the axial displacement of the disc and in consequence the opening of the scavenging valve s, naturally will be increased. he larger quantity of air discharged into the atmos phere on heavy breathing is rendered neces K sary by the fact that increased breathing will von its passage to prevent condensation of cause an increased consumption of oxygen, whereby the quantity of the nitrogen admitting with the oxygen and requiring to be removed will grow. In the known scavenging valves and also in those according to Figs. l to 4 the control o-f the quantity flowing out p is eiiected automatically through the superpressure set up in front of the scavenging opening, vwhich pressure again is dependent on the breathing force, since for the passage of those portions of the circulating system situated behind the exhaling valve up to the bag, a drop of pressure is necessary, which willgrow with increased breathing. But a device accordingto Figure 5 can be arranged directly in front of the breathing bag, so that no considerable variablesuper-pressure over the atmosphere is available for operatingy the scavenging valve, and consequentlya diiierent control of the scavenging quantity flowing off must be provided. y

It is obvious, that in using a device ac cording to Figure 5. the exhaling valve might perhaps be entirely dispensed with. Nith an unfavorable position of the exihaling valve it might prove necessary to substitute the scavenging valve according to Figure 5 for that shown in Figure il. In the same way pipesf having a calibrated boring g according to Figure 1,may be connected to the scavenging valves according to vFigures i and 5, and there maybe eli'ected' other variations and combinations.

In arranging the pipe f and the calibrated boring g it is essential that the said boring g is situated at a safe place and that the pipe f lies within the region of influence of the cartridge in such a way, that the scavenging air flowing out willfbe raised .in temperature moisture.

The present invention shows the following advantages over known scavenging valves:

As the scavenging valve is operated by a closing member for the circulating system, the opening of the scavenging valve at each exhalation is ensured. If the scavenging valve should not open, the closingmember too would remain closed and the bearer of the device would experience an unsurmountable resistance when exhaling. Likewise a faultless closing of the .scavenging valve is ensured. As this valve will open positively under any condition during the exhalation, the loading spring may be of such strength,

that the said valve will close tightly during inhalation. The closing is furthermore assisted by the fact that. the pressure below normal set up at the mouth piece will exist l also at the closing member. The tight seat eventually is improved because after afew breaths condensate will collect at the scavenging valve, in consequence of which a water-seal is formed on the valve seat, which 130 Will close any unsealed places which still might exist.

On account of the spatial separation of scavenging valve and calibrated scavengingv boring it is possible` to arrange the scavenging valve at any desired point in the breathing cycle, Without fearing any choking. It is al- Ways possible to arrange the scavenging boring at a place Which is protected against becoming dirty. The length and the form of the connection pipe is immaterial,

If the said connection pipe is arranged in such a manner that it lies Within the region of influence of the cartridge, a further and highly essential advantage is obtained in view of the fact that the eXhaling air is Vsaturated With moisture at themoment of eX- halation. The said air will cool dovvnin a normal Way during its passage to the cartridge, so that condensate Willbe separated out. As stated above such condensate can become dangerous ifit passes into the scavenging boring. This danger is removed by the arrangement according to the invention in that the discharged air, flowing through the pipe f,.will be raised in temperature in consequence of the raised temperature of the cartridge. As a result the capacity for absorbing Water vapors up to the degree of saturation Will increase, thereby not only preventing the condensation of vapor but vaporizing again and carrying oil' any condensate which might have flowed in. It is not necessary that the air continuously increase in temperature on its entire passagethrough the conduitf. When the conduit f is of sufficient cross-sectional area it Will be sufficient, if the temperature rises in the last f part from f to g.

I claim:

In a breathing apparatus having a closed breathing circuit adapted to be periodically scavenged to prevent the accumulation of' nitrogen therein, the combination of a scavenging valve controlling a discharge' conduit, and an eXhallng valve arranged 1n sald circuit and adapted to be moved by the pressure of the exhaled air, said valves being integrally connected in the form of a substany tially flat disc.

In testimony whereof I aiiiX my signature.

WILHELM TAMM. 

